When discussing the stability of proteins, I mostly think of their folding, not whether their primary or secondary structure breaks.
The free energy difference between folded and unfolded states of a typical protein is allegedly (not an expert!) in the range 21-63 kJ/mol. So way less than a single covalent bond.
I have a friend who does his physics PhD on protein folding, and from what I remember he mostly simulates the surface charge of proteins, i.e. cares about dipole-dipole interactions (the weaker version of ionic bonds) and interaction effects with the surrounding water (again dipole-dipole afaict).
This suggests that vdW forces aren’t all that important, but the energy scale you get from imagining vdW forces is still way better than when imagining covalent bonds.
Regarding how to do enzyme-like catalysts with covalent nanotech: my first guess is that we’d want to build a structure that has several “folded”/usable states close in energy, e.g. due to rotational degrees of freedoms in the covalent bonds. This way “unfolding”/breaking the machine requires a lot of energy, while it can still mechanically move to catalyze a chemical reaction at low activation energies.
Addendum: I just learned that dipole-dipole interaction are classified as a type of vdW force in chemistry. This is different from solid state physics, where vdW is reserved for the quantum mechanical effect of induced dipole—induced dipole interaction.
So it’s indeed vdW forces that keep a protein in its shape. (This might also explain why OP found different oom for their strength?)
When discussing the stability of proteins, I mostly think of their folding, not whether their primary or secondary structure breaks.
The free energy difference between folded and unfolded states of a typical protein is allegedly (not an expert!) in the range 21-63 kJ/mol. So way less than a single covalent bond.
I have a friend who does his physics PhD on protein folding, and from what I remember he mostly simulates the surface charge of proteins, i.e. cares about dipole-dipole interactions (the weaker version of ionic bonds) and interaction effects with the surrounding water (again dipole-dipole afaict).
This suggests that vdW forces aren’t all that important, but the energy scale you get from imagining vdW forces is still way better than when imagining covalent bonds.
Regarding how to do enzyme-like catalysts with covalent nanotech: my first guess is that we’d want to build a structure that has several “folded”/usable states close in energy, e.g. due to rotational degrees of freedoms in the covalent bonds. This way “unfolding”/breaking the machine requires a lot of energy, while it can still mechanically move to catalyze a chemical reaction at low activation energies.
Addendum: I just learned that dipole-dipole interaction are classified as a type of vdW force in chemistry. This is different from solid state physics, where vdW is reserved for the quantum mechanical effect of induced dipole—induced dipole interaction.
So it’s indeed vdW forces that keep a protein in its shape. (This might also explain why OP found different oom for their strength?)